


Apple Bottom Cheeks

by chromyrose



Category: Haikyuu!!
Genre: Breasts, F/M, Lingerie, No Sex, Partial Nudity, Sibling Incest
Language: English
Status: Completed
Published: 2016-04-04
Updated: 2016-04-04
Packaged: 2018-05-31 06:19:46
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,595
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/6459190
Author URL: https://archiveofourown.org/users/chromyrose/pseuds/chromyrose
Summary: <blockquote class="userstuff">
              <p>Ryuu finds his sister's lingerie in his laundry. The ensuing confrontation doesn't go exactly as planned.</p>
            </blockquote>





	Apple Bottom Cheeks

**Author's Note:**

  * For [ColonelChanSan](https://archiveofourown.org/users/ColonelChanSan/gifts).



> A few months ago I saw a request for Tanakacest on the lj hqkinkmeme and I thought "Hey, that could be fun!" But then I started to write it and my silly morals got in the way of the fun part. Recently, though, I was talking to [a friend](http://archiveofourown.org/users/colonelchansan) about incest ships and this fic came up, and she convinced me to dig it out and finish it up. So this fic goes out to you, Vicki. 
> 
> **PLEASE NOTE THE TAGS**. If you don't like brother/sister incest, this isn't the place for you. No genitals become involved, but there's still enough innocent sibling exploration in here that if you're uncomfortable with the subject matter, it might be best to give it a miss.

After the Tokyo training camp, Ryuunosuke had a shit ton of laundry that needed to get done. Practice shirts with sweat stains that lingered even a week later, black shorts, a week's worth of underwear, and a mountain of socks large enough to lose a child in – but if he was being honest, he didn't really mind. He took the bag of dirty clothes and some of his homework down to the tiny space where the washer and dryer were stashed, and got more of his assignments done than he'd expected to thanks to the calming scent of detergent and the rhythmic spinning of the appliances. 

Three hours later, he knelt in front of the dryer and scooped the hot clothes out, hissing curses under his breath whenever his fingers brushed the fiery metal drum. Ryuunosuke hand-spun the machine to make sure none of his socks went unpaired, because he didn't want to have to come all the way back down for anything that might've been left behind; instead of finding another sock tucked inside of the dryer, his hand came out with a lacy scarlet thong. 

His brain operated on auto and he flung the offending garment down on top of his pile of clean clothes, feeling his ears turn bright red. It took a moment before his mind was able to figure out how a girl's lingerie ended up with his laundry. 

“Saeko!” He hollered, snatching the thong and stomping up the stairs to the kitchen. “What the fuck is this?!”

Saeko looked up from the pot she was stirring over the stove, blinked, and then grinned. “Oh damn, I thought I'd lost this!” She said gleefully, snatching it from Ryuunosuke and then shoving it into her back pocket haphazardly; most of the lacy thing was hanging down like a fiery beacon over the ass of her jeans. “Come taste this curry sauce for me, I can't remember if I put salt or not.” 

“We are not talking about that,” Ryuunosuke scoffed, swatting her ladle away. “It'll be fine without salt; Dad could probably use some cutting back on it, anyways. But, no, right now we're talking about you, having that!”

Saeko took a sip from the ladle herself, and then hummed. “You know, you're right little bro. Good thinking.” As she reached for the salt dispenser, she wiggled her butt, shaking the thong back and forth like a red flag. 

“Ugh,” Ryuunosuke groaned. “Ugggggh! Men are never going to respect you like this!”

At that, Saeko laughed. She put the ladle down and pet her brother's cropped hair. “You don't understand because you're so honorable, baby bro. You like honorable girls, like Shimizu-chan.”

“And you should like honorable guys! You should be an honorable girl!” Ryuunosuke insisted, feeling his cheeks go pink. Normally he'd resist the compliment, but he had more important things on his mind. 

Saeko laughed again, and her hand slid down from the top of Ryuu's head to cup his cheek; immediately, his scowl softened. 

“You are _so_ sweet, it's almost too bad you're my baby brother,” she cooed. “I can't believe you don't already have a girlfriend! I wish I could show all those girls what they're missing.” 

Ryuunosuke snorted and shooed her hand away. “Well, think of yourself that way! There are guys on the team who think you're hot, really good guys. So you don't have to be _that_ kind of girl.”

“Ooooh,” Saeko gasps. “Who is it? Probably not Yuu-chan, I'm pretty sure he's gay...” 

“Oi, what? Noya's not gay!” 

“What, haven't you seen how he looks at Azumane?” Saeko clasped her hands together beside her cheek, and fluttered her eyelashes like a cartoon character in love. 

“...Wait, what, seriously – no, _no_. Stop distracting me! And stop trying to figure out who, too! Who it is doesn't matter. What matters is that he exists and that he isn't the kind of skeevy guy who needs to see you in stuff like that,” Ryuunosuke insisted, pointing at her butt. Saeko was grinning again, but now it looked a little more like a leer. 

“Oh, my little baby brother,” she drawled. “You've never seen a girl in a thong, have you?” 

“Uh...?”

“And here I thought guys on sports teams snickered at playboys and porn rags during their downtime,” She sighed. “But that can't be true, because if you had seen that kind of stuff, you would know the power it has over all guys. Not just the skeevy ones.”

Saeko hummed to herself, and then grinned at him. “You're much more innocent than I thought, Ryuu!” 

Ryuunosuke didn't answer, because his mind was stuck trying desperately not to imagine Kiyoko-san in something like his sister's lingerie. He snapped out of it when he heard the burner of the stove click off, and the thoughtful look on Saeko's face scared him a little bit. 

“You look like such a badass, Ryuu, it didn't even occur to me you had no experience with this stuff,” Saeko said finally, after she turned around to face him. She was reaching into her back pocket, and she pulled the thong out and stretched it out between her fingers so the entire barely-there of it could be seen. 

“But, what are older sisters for if not to teach you the important stuff?”

–

Ryuunosuke was more than faintly aware that probably no religion on Earth would take him after this. As he sat squirming on Saeko's bed, he wondered if maybe he wasn't going to ignite the moment he stepped onto the shrine grounds next New Year's. Not that he'd ever seen something like that happen before, but he figured there weren't probably many people in Miyagi who listened when their older sisters told them to ' _Sit tight_ ,' so she could go change into lingerie for them.

Saeko pushed the door open without ceremony, and strode into her room with her typical confidence. She was swiveling her hips a little more than usual, though, which drew Ryuunosuke's gaze down from her sultry smirk, past her typical black shirt, to the long, smooth tan skin of her legs. With excitement and shame mingling in his gut, Ryuunosuke mused that he was the impressionable little brother, and Saeko was the unfair temptress who should go up in flames after this.

Also, he'd never again be able to get mad at Kinoshita for the “hot sister” comments. 

After she shut the door, Saeko leaned against it, and her hands went to the hem of her long shirt. She pulled it up slowly, exposing the curve of her hips, and the instigating red thong. It was little more than a scrap of fabric covering her most sensitive area, but somehow that facade of modesty was more arousing than if she'd just been naked. Ryuunosuke was beginning to see the appeal. 

“I'm not too bad, am I, little bro?” She asked airily, with a chuckle in her voice. “Wait til you see the best part, though.” 

She turned around without hesitation, and leaned forward; the entire lace back of the lingerie made it so that the dimpled skin of her ass _just_ peeked through. Again, an illusion of modesty that might have been more lewd than actual nudity. 

Ryuunosuke's dry throat made a choked noise, and Saeko giggled. She stood upright again, her posture friendly, no longer hungry. She climbed him on the bed beside him and kissed Ryuunosuke's cheek. 

“What does it make you wanna do?” 

“Uh... touch, I guess,” he stammered. Ryuunosuke couldn't see for himself, but he figured with the way they were giving off heat, his ears were probably as red as her underwear. 

“Good thinking,” Saeko agreed, peeling her large, black shirt off to reveal a bra made from the same lacy scarlet as the panties. 

“Oh my god, you're the worst,” Ryuunosuke groaned, shaking his miserable head. He was so turned on, and the shame was giving him a splitting headache. 

“I'm terrible,” she echoed, taking one of his hands in hers. “This might be a good time to make this clear: I don't totally lust after you day in and day out. But you're my brother. I love you. I trust you. This is gonna be good for me and I'm gonna do my best to make it good for you, too.” 

“Oh my god,” he whined. As if he wasn't flushed enough just being turned on, now he was just this side of feeling embarrassed. But there was too much warmth in his sister's voice and eyes, even a little furrow in her brow that was probably concern, for Ryuunosuke to feel truly humiliated.

Saeko laughed again, and just to get her to shut up, Ryuunosuke dropped his heavy hand on her shoulder, dragged it down to the swell of her breast, and then squeezed, hard. The way his sister shuddered was kind of incredible in it's own right, but Ryuu was more dazed by the heavy feeling in his palms. “Shit, they're soft...” 

“Duh,” she responded a little breathlessly. “They'll be even softer without the bra, though. If you wanna try taking it off?”

The wording almost made it sound like a challenge, but Ryuunosuke couldn't see how it would be hard to remove a piece of underwear. Until his hands went to the band, traced it on either side, and realized how stiff it was.

“Is this secretly some kind of medieval torture device?” He wondered, feeling the underwire – was there really metal in bras? 

“More like a torture device of the modern patriarchy,” Saeko replied with a grin. “They used worse stuff back then. But hey, torture device or not, they make my boobs look good. And the support's pretty important for well-endowed girls, ya know.” She winked and shifted so one of her very ample boobs would brush against Ryuunosuke's hand. He tried to pretend he wasn't affected.

“Clasp in the back, by the way,” she added. “For most of your standard issue bras, anyones. Some have front clasps. And you were gonna pull it up? That would work for sports bras, I guess, but I doubt a girl would wear a sports bra to have sex unless she was caught off guard, or knew you well enough not to care anymore.”

Ryuunosuke filed the information away for the future, even though he was a little annoyed that he had failed in just the way his sister had expected. His hands went around her back, bringing their chests close enough that her boobs were touching him, if not pressed against him in their entirety. He had to look over her shoulder to get a glimpse of how the clasp worked, but it was simple to unhook it after that. Ryuunosuke pulled back after that, and Saeko let the straps of her bra slide down her arms, peeling it away and putting it aside. 

She looked up at her brother with a sheepish smile, a little bit of pink in her cheeks that Ryuunosuke had never before seen on her unless she was drunk. It was sort of endearing, and made it a little easier for him to look down at her bared breasts. 

Saeko had an ample chest, that much was obvious even when she was fully clothed, but in the flesh it was a surprise how small her nipple was by comparison; out of curiousity, Ryuu pinched it between his forefingers. Saeko hissed. 

“Fuck,” she swore a little breathlessly. “You seemed pretty sure that'd work. Do it to yourself?” 

“Of course not!” He responded in a huff, pinching her nipple again in annoyance. Saeko laughed, and pulled on his shirt. 

“Let me show you,” she said as she tried to get his shirt above his pectorals. Even with his arms being uncooperative, Saeko managed to get a hand up Ryuunosuke's chest, and she rubbed one of his nipples with the pad of her thumb until it was swollen and hard before rolling it between her fingers. 

Ryuunosuke bit his lip to keep the groan that bubbled up his throat from spilling out. Saeko's free hand was quickly there to pull his lip loose, and when he tried to glare at her, she just gazed back with an indulgent smile. 

“I'm not about to be the only one of us who gets naked today, baby brother.” 

He huffed. “Quit calling me that, okay? How would you feel if I called you 'big sis' while we did this kind of thing, huh?” 

Saeko paused suddenly to tilt her head; some of her blonde hair brushed over her shoulder beautifully. “That would be insanely fucking hot,” she decided finally, grinning from ear to ear. Ryuunosuke shook his head, but didn't have time to say anything before she was tugging his shirt up against his shoulders. 

With a small sigh, he complied, lifting his arms up so his shirt could come off. It wasn't as if he didn't take his shirt off on a regular basis, so there was nothing embarrassing about that kind of exposure. But the fact that they were _both_ shirtless was a little stirring. 

Saeko kissed his sharp collarbone, and rather than being arousing, it was as sisterly as ever; that didn't stop warmth from blooming in Ryuunosuke's stomach. 

“How far do you want this to go?” She asked. Ryuunosuke's gaze immediately darted down to her underwear before he regained control over his eyes and looked up at her, a little flustered.

“Definitely not _that_ far,” he grumbled. “You are my sister.” 

“Fair enough,” Saeko agreed. “They say incest babies are more likely to come out with a bunch of problems? And you already shove your hands down your gym shorts to 'look tough', so it's probably best not to push our luck.”

“Hey!” 

“Besides,” she added after a quick snigger. “You first time should be with a girl you like. Not the girl you remembers your 'pee on everything' phase.” 

Ryuunosuke shoves Saeko a bit meanly. “I was three, I don't even remember it myself. Let it die already!” 

Her breasts bounced as wobbled over and caught herself, and she laughed at Ryuunosuke's expense; it was really perverse, how normal they were acting when her boobs were just hanging out, when she was only wearing a scrap of fabric over her modesty. 

“But you never answered my question,” she said, cutting into Ryuunosuke's thoughts. “How far are you comfortable going? Blowjob? Handjob? Wanna suck my tits?” 

She waggled her eyebrows and Ryuunosuke felt a fierce blush coming on. 

“Uh, none of the above? I'm good for now. So... yeah.” 

An expression flickered on Saeko's face so quickly that Ryuunosuke couldn't tell exactly what it was. But then she was smiling, and reaching for her shirt. 

“Good. And, uh, promise me one more time you don't totally hate me now?”

Ah. “Of course I don't hate you, Sae – big sis.” 

When her head popped out of her shirt, Saeko looked pleased. She leaned in and gave Ryuunosuke a big kiss on his head, and then went to her closet to grab some shorts. 

“You're gonna be a total heartbreaker, Ryuu. I'll call you when dinner's ready, but til then, you might wanna take care of – that.” 

Saeko pointed flippantly to his crotch, where his half-hard dick was flagging in his shorts, and then winked. She strode out of her bedroom sassily, leaving Ryuunosuke there with the unsaid retort to die on his tongue. 

If that's what he got for doing laundry, Ryuunosuke mused, he was probably not going to be doing laundry again for while.

**Author's Note:**

> Hey, look at you, you made it, way to go! Check me out in other places if you think I'm cool: [twitter](https://twitter.com/haikyuutiie) | [tumblr](http://zahhaked.tumblr.com)


End file.
